In Providing Evidence of Penetration Condom traces found inside a victim can provide evidence of penetration. In many jurisdictions, this evidence raises the charge to a higher degree of sexual assault. In Producing Associative Evidence Recovered condom traces may correspond to those found in a certain brand or used by a certain manufacturer. An empty packet of this particular brand found near the crime scene, especially if it bears the suspect’s fingerprints, provides a strong association between the suspect and the crime. Unopened condom packages of this same brand found on the suspect, in his car, or at his residence also would help tie the suspect to the crime.
In Linking the Acts of Serial Rapists People tend to be creatures of habit, and sexual criminals are no exception. A serial rapist likely will use the same brand of condom to commit repeated acts. Moreover, repeat offenders whose DNA profiles have been stored in a computer data bank may be likely to use a condom when committing subsequent crimes. Along with other aspects of his modus operandi, traces from the same condom brand or manufacturer found during several different investigations can help connect a suspect to an entire series of assaults.
Guidelines For Evidence Collection
Investigators need not make any drastic changes in their usual procedures in order to include the possibility of condom trace evidence. The following guidelines will assist criminal investigators and medical examiners when collecting this valuable evidence.3
At the Crime Scene
First and foremost, investigators must wear powder-free gloves to protect themselves from bloodborne pathogens and to avoid leaving particulates that may be similar to those contained in some condom brands.
After collecting the evidence, they should package the gloves separately and submit them with the evidence so that the forensic laboratory can verify that the gloves did not leave behind any particulates.
At the crime scene, investigators should make every effort to locate any used condom and its foil package. If a condom is recovered, the traces from the victim on the outside and the seminal fluids from the assailant on the inside would have the greatest evidentiary value. If investigators find an empty condom packet, they first should try to recover any latent prints from the outside. The inside of the package probably will not contain prints, but may contain lubricant, spermicide, and particulate residues. Investigators should wipe the inside with a clean cotton swab. The traces on this swab will serve as the standard for comparison with traces recovered from the victim and the suspect.
During Medical Examinations
Most commercial sexual assault examination kits provide two cotton swabs for each type of examination, i.e., vaginal, penile, etc. In the past, before assailants began using condoms frequently, these two swabs proved adequate–one swab for immediate examination and a second in case the defense team requested another examination by its own experts or by an independent laboratory.
With sexual offender’s using condoms, however, forensic laboratories should use three swabs: One to save for the defense and two to conduct examinations. With the potential for positively identifying a suspect, most laboratories first look for traces of seminal fluids, vaginal cells, blood, and the like. Unfortunately, the solvents used to conduct this examination also remove any condom traces present, thus losing potentially valuable evidence.
Although examiners feasibly could divide each swab in half, providing an additional swab in kits for each condom trace examination easily could solve the problem.
The gloves provided in commercial examination kits usually come powder-free. However, the medical personnel who examine sexual offenders and their victims frequently prefer the gloves they normally wear, which often contain the same powders (corn starch, amorphous silica, and talc) found on many condom brands. While medical staff members may insist that their collection procedures are above reproach, forensic examiners cannot guarantee the integrity of the condom trace evidence if the medical staff wears their own gloves.
In short, investigators must persuade examining personnel to wear unpowdered gloves. After the medical examinations, investigators should recover and separately package the used gloves. The forensic laboratory then can confirm that the gloves were powder-free.